This part is commonly Used on models:
78315 37"" Side Discharge Mower
78345 42"" Side Discharge Mower
78346 42"" Side Discharge Mower
78360 48"" Side Discharge Mower
78347 42"" Side Discharge Mower
78368 48"" Side Discharge Mower
78365 48"" Recycler Cutting Unit, 300 Series GT Classic Tractors
